Parting tool for well casings



H. C. DENNING.

PARTING TOOL FORIWELL CASINGS- APPLICATION FILED MAY'H, 1921.

rammed Apr. 18, 1922.

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To allwhom-z'tmay c0ncem: I Be it known that'I, HOMER C. DENNING, a citizen of the United States, residing at Lance Creek, in the county of Niobrara and State of Wyoming, have invented certain new and nseful Improvements in Parting Tools' for Well Casings; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which 1t appertains to make and use the same.

The invention relates to a special tool ior sections of casings of driven or bored we ls be pulled or withdrawn from the well, and to this end comprises a tool adapted tb be attached to the lower end of the drill jars or other suitable element, secured to the end of the cable or drill rope, said tool including a generally cylindrical body fitting the tubu-1 lar well casing, having a longitudinal slot therein in which is mounted a blade having 'a cutting edge at-its outerend and a plvotal connection within the slot at its inner end, so that, when the blade is turned to 1ts upward position within the slot, the cutting edge thereof will be automatically projected beyond the walls of the slot and engage the lower edge of thecasing section to be cut or slit, the cutting or slitting operation being efi'ected by intermittent pulls or blows de-" livered to the tool by the operation of the drill rig, as will be more particularly pointed outhereinafter,

. In the accompanying drawings Fig. 1 is a vertical section through a portion of a well casing with the parting tool in operative relation therein;

Flg. 2 is a similar view showing the lower end of the casing sectio'ncutor slit and separated from the subjacent section;

Fig. 3 is a fragmentaryview, partly in section, of the partlng tool with a special thimble attachment applied thereto; and

Fig. 4 is a transverse section on line 44. of F1 3. I

Referring to the drawings, 1 indicates the body of the parting toolwhich is preferably formed as a generally cylindricalelement having a reduced neck or, wrench portion 2 and a screw-threaded boss'3 on its upper end adapted to take in the screw-threaded socket in the lower member 4 of the usual set of drill jars employed in apparatus of this kind, which jars are operatively su ported within the well casing, with the other Specification o1inatteraZtatent. Patented Application filed May 14,

0 permit the casing to tangential to the or drill rope, through the casing to the oiperatin rig. The body 1 of the tool is of su cient iame- Apr. 18, 192 2.

' elements of the tool string, fromth cable which latter extends up. I

ter to allow a small clearance-space between it and the inner walls of the casm The body tom of the tool upwardly and having intermed1ate 1ts length a rounded concavity forming an abutnient 6, the bottom of the slot be-- sald concavity being inclined out 1 yond wardly as at 7 t v 'Mounted for pivotal or .swinging movement within the slot.

1 of thetool is provlded'with I a long tudinal slot 5 extending from thebotat w 5 is a cutting blade or ,k'mfe 8, the inner end of which is provided.

with a generally circular enlargement 9 provided with an arcuate slot 10- to receive a pivot pin '15Tpassing transversely through the bodfi 1. cutting lade is provided with a cutting he outer end of the knife or edge 11, .as indicated. The body of the bade 8 is provided with a rear edge, substantially As indicated, the tool is designed to cut or slit the lower end of a selected casing section to y within the slot, ,so' be lowered in' the casing' permit the same to be separated from the 'coupling, which unites it with section,

to permit all of the casing sections above the slitted member to be withdrawn from the .well. To eifect this result'the tool I is attached to the lower member of the tool string of a standard drill ring, andprefthe next subjacent erably to the lower member of the jars, as

indicated, with the cutter blade or knife 8 turned to its upper position,.as indicated in Figfil, and the tool string lowered into the casing by the drill rope or cable until the parting tool is adjacent the' particular casing section to be separated or parted from those lying below the same; During the downward movement of the tool string the knife or cutterblade 8 lies within the upper portion of slot and offers no obstruction to the movement of the tool string downwardly in the casing. When the toolreaches thelower end of the casing section to be operated upon, the movement of the drill rope or cable is reversed and the tool string moved upward1y,which. has theeflect of causing the oute'rkcutting edge 11 of the knife or cutter blade 8 to move outwardly and engage thelower end of the casing section, such as B, where the latter engages the coupling member C which connects it with the subjacent casing section A. The upward pull or strain on the cable causes the cutting edge 'of the knife to'wedge in between the lower end of the casing section B and the inner wall of the coupling'C, and at the same time forces the body 1 of the tool into engagement with the opposite wall of the casl ing and effectively wedges the tool in -posi-:

the coupling member 0. During, the cut-' tmg operation the heavy downward thrust imposed on the knife 8 is taken up by the engagement of the rounded part or lower section of the knife engaging the rounded abutment '6 formed in the bottom of the slot 5, as indicated in Fig. 1, so that no severe strains are put upon the pivot pin 15 which works freely in the ai'cuate slot 10.

' As soon as the pipe section'B hasbeen part ed or separated from the coupling C, up-

- stantially the same diameter as the bore ofward pull on the drill cable will cause the knife or cutter blade 8 to swing on its pivot 15 to the position shown in Figs. 2 and 3, with the blade extending downwardly and occupying the lower section of the slot 5, so that the tool may be readily withdraw from the casing. I

In order to adapt the tool for use in casings of different sizes, the upper portion of the tool body is provided with a reduced section 12-terminating in a shoulder to receive and support adapter thimbles of varying sizes to fit the various diameters of the casing sections. For example, in the embodiment of the invention shown in Figs. 1 and 2, in which the body of the'tool 1 is of subthe casing, the adapter collar 13 is employed only to carry out the normal contour of the tool and obviate'sharp angles in the tool which might tend to cause jamming of the tool at the casing joints. In Fig. 3, how ever, the tool is adapted to be applied to a casing of larger diameter than that shown in Figs. 1 and 2, and to meet the exigencies of this case there is pfovided a. thimble 13' .and the thimble.

-which substantially encloses the lower portion of the tool and is of\substantially the same diameter as the bore of the casing. In order to maintain the cutter blade or knife 8, however, 7 in proper relation to the end of the casing section to be cut or slit, the thimble 13'- is provided with an eccentric bore into which the tool body 1 fits and with a slot 5 which registers ,with the slot 5 in the tool body which will admit of the cutting end of the knife, when the latter is in operative position, extending through the registering slots 5 and 5' and properly engaging'the end of the casing section. It will be understood that the adapterthimbles may be made in different sizes to operate in casin of .various diameters, which will, there ore, enable a single standard parting tool to be employedffor practically all sizes of casings, within reasonable limits. The thimble sections 13, 5 13" are secured to the tool by means of the cross pin or pins 14 engagingregistering holes the tool body 1 In order to produce the most efficient cutting .and rippingejfect on-the casing ends, the knife or cutteFblade 8 in its operative position should be as nearly vertical as possible. On the other hand,the knife must be inclined sufiiciently'to produce a material lateral component of the thrust, when the knife is drawn into engagement with the casing end, to cause an effective binding or locking of the tool in the casing during the cutting operation, which latter is affected by successive impacts on the knife by the upward movements of the cable, after the knife has beenengaged with-the casing end at the point to be cut or ripped.

What I claim is': 1. A tool for cutting well casing sections comprising a tool body having a longitudinal slot therein, and an elongated blade having a cutting edge at its outer end and a pivotal cormection at its inner end within said slot, said blade being normally supported at its pivot end insubstantially up- .right' position in said slot, whereby the outer end of the blade will engage and cut the end of the casing section when the tool is moved upwardly.

2. A tool for cutting well casing sections comprising a tool bodyhaving a longitudinal slottherein, an elongated blade having a cutting edge at its outer end and a pivotal connection within said slot approximately intermediate the ends of the latter, said slot having an abutment in its bottom cooperating with the end of the blade to receive the shock of impact on the tool when the latter is in upright position and moved upwardly to effect the cutting operation.

3. A tool for cutting well casing sections comprising a tool body having a longitudinal slot therein provided with a rounded concavity intermediate its length, and a blade pivotally mounted in said slot, said blade having a cutting edge at its outer end and ,a rounded section at its inner end engaging the bottom of said concavity, said blade being normally supported at its pivot end in substantially upright position in said slot, whereby the outer end of the blade will engage and cut the end of the casing section when the tool is moved upwardly.

4. A tool for cutting Well casing sections comprising a substantially cylindrical body portion having a longitudinal slot therein, a blade pivotally mounted in said slot and having an outer cutting edge, and auxiliary thimbles of varying diameters adapted to be mounted on the tool body to increase the diameter of the tool to substantially that of the interior of the casing sections.

5. A tool for cutting Well casing sections comprising a substantially cylindrical body the tool body fits and longitudinal slots reg- 30 istering with the slot in the tool body.

In testimony whereof I afiix my signature.

HOMER C. DENNING. 

